// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __I_MESH_CACHE_H_INCLUDED__
#define __I_MESH_CACHE_H_INCLUDED__

#include "IReferenceCounted.h"

namespace ldx
{

	namespace scene
	{
		class IMesh;
		class IAnimatedMesh;
		class IAnimatedMeshSceneNode;
		class IMeshLoader;

		//! The mesh cache stores already loaded meshes and provides an interface to them.
		/** You can access it using ISceneManager::getMeshCache(). All existing
		scene managers will return a pointer to the same mesh cache, because it
		is shared between them. With this interface, it is possible to manually
		add new loaded meshes (if ISceneManager::getMesh() is not sufficient),
		to remove them and to iterate through already loaded meshes. */
		class IMeshCache : public virtual IReferenceCounted
		{
		public:

			//! Destructor
			virtual ~IMeshCache() {}

			//! Adds a mesh to the internal list of loaded meshes.
			/** Usually, CSceneManager::getMesh() is called to load a mesh
			from a file. That method searches the list of loaded meshes if
			a mesh has already been loaded and returns a pointer to if it
			is in that list and already in memory. Otherwise it loads the
			mesh. With IMeshCache::addMesh(), it is possible to pretend
			that a mesh already has been loaded. This method can be used
			for example by mesh loaders who need to load more than one mesh
			with one call. They can add additional meshes with this method
			to the scene manager. The COLLADA loader for example uses this
			method.
			\param name Name of the mesh. When calling
			CSceneManager::getMesh() with this name it will return the mesh
			set by this method.
			\param mesh Pointer to a mesh which will now be referenced by
			this name. */
			virtual void addMesh(const std::string& name, IAnimatedMesh* mesh) = 0;

			//! Removes the mesh from the cache.
			/** After loading a mesh with getMesh(), the mesh can be
			removed from the cache using this method, freeing a lot of
			memory.
			\param mesh Pointer to the mesh which shall be removed. */
			virtual void removeMesh(const IMesh* const mesh) = 0;

			//! Returns amount of loaded meshes in the cache.
			/** You can load new meshes into the cache using getMesh() and
			addMesh(). If you ever need to access the internal mesh cache,
			you can do this using removeMesh(), getMeshNumber(),
			getMeshByIndex() and getMeshName().
			\return Number of meshes in cache. */
			virtual mt::uint getMeshCount() const = 0;

			//! Returns current index number of the mesh or -1 when not found.
			/** \param mesh Pointer to the mesh to search for.
			\return Index of the mesh in the cache, or -1 if not found. */
			virtual int getMeshIndex(const IMesh* const mesh) const = 0;

			//! Returns a mesh based on its index number.
			/** \param index: Index of the mesh, number between 0 and
			getMeshCount()-1.
			Note that this number is only valid until a new mesh is loaded
			or removed.
			\return Pointer to the mesh or 0 if there is none with this
			number. */
			virtual IAnimatedMesh* getMeshByIndex(mt::uint index) = 0;

			//! Returns a mesh based on its name.
			/** \param name Name of the mesh. Usually a filename.
			\return Pointer to the mesh or 0 if there is none with this number. */
			virtual IAnimatedMesh* getMeshByName(const std::string& name) = 0;

			//! Get the name of a loaded mesh, based on its index.
			/** \param index: Index of the mesh, number between 0 and getMeshCount()-1.
			\return The name if mesh was found and has a name, else	the path is empty. */
			virtual const std::string& getMeshName(mt::uint index) const = 0;

			//! Get the name of the loaded mesh if there is any.
			/** \param mesh Pointer to mesh to query.
			\return The name if mesh was found and has a name, else	the path is empty. */
			virtual const std::string& getMeshName(const IMesh* const mesh) const = 0;

			//! Renames a loaded mesh.
			/** Note that renaming meshes might change the ordering of the
			meshes, and so the index of the meshes as returned by
			getMeshIndex() or taken by some methods will change.
			\param index The index of the mesh in the cache.
			\param name New name for the mesh.
			\return True if mesh was renamed. */
			virtual bool renameMesh(mt::uint index, const std::string& name) = 0;

			//! Renames the loaded mesh
			/** Note that renaming meshes might change the ordering of the
			meshes, and so the index of the meshes as returned by
			getMeshIndex() or taken by some methods will change.
			\param mesh Mesh to be renamed.
			\param name New name for the mesh.
			\return True if mesh was renamed. */
			virtual bool renameMesh(const IMesh* const mesh, const std::string& name) = 0;

			//! Check if a mesh was already loaded.
			/** \param name Name of the mesh. Usually a filename.
			\return True if the mesh has been loaded, else false. */
			virtual bool isMeshLoaded(const std::string& name) = 0;

			//! Clears the whole mesh cache, removing all meshes.
			/** All meshes will be reloaded completely when using ISceneManager::getMesh()
			after calling this method.
			Warning: If you have pointers to meshes that were loaded with ISceneManager::getMesh()
			and you did not grab them, then they may become invalid. */
			virtual void clear() = 0;

			//! Clears all meshes that are held in the mesh cache but not used anywhere else.
			/** Warning: If you have pointers to meshes that were loaded with ISceneManager::getMesh()
			and you did not grab them, then they may become invalid. */
			virtual void clearUnusedMeshes() = 0;
		};


	} // end namespace scene
} // end namespace irr

#endif

